1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef UI_BASE_L10N_L10N_UTIL_COLLATOR_H_ 6 #define UI_BASE_L10N_L10N_UTIL_COLLATOR_H_ 7 8 #include <algorithm> 9 #include <functional> 10 #include <string> 11 #include <vector> 12 13 #include "base/i18n/string_compare.h" 14 #include "base/memory/scoped_ptr.h" 15 #include "third_party/icu/source/i18n/unicode/coll.h" 16 #include "ui/base/ui_export.h" 17 18 namespace l10n_util { 19 20 // Used by SortStringsUsingMethod. Invokes a method on the objects passed to 21 // operator (), comparing the string results using a collator. 22 template <class T, class Method> 23 class StringMethodComparatorWithCollator 24 : public std::binary_function<const string16&, 25 const string16&, 26 bool> { 27 public: 28 StringMethodComparatorWithCollator(icu::Collator* collator, Method method) 29 : collator_(collator), 30 method_(method) { } 31 32 // Returns true if lhs preceeds rhs. 33 bool operator() (T* lhs_t, T* rhs_t) { 34 return base::i18n::CompareString16WithCollator(collator_, 35 (lhs_t->*method_)(), (rhs_t->*method_)()) == UCOL_LESS; 36 } 37 38 private: 39 icu::Collator* collator_; 40 Method method_; 41 }; 42 43 // Used by SortStringsUsingMethod. Invokes a method on the objects passed to 44 // operator (), comparing the string results using <. 45 template <class T, class Method> 46 class StringMethodComparator : public std::binary_function<const string16&, 47 const string16&, 48 bool> { 49 public: 50 explicit StringMethodComparator(Method method) : method_(method) { } 51 52 // Returns true if lhs preceeds rhs. 53 bool operator() (T* lhs_t, T* rhs_t) { 54 return (lhs_t->*method_)() < (rhs_t->*method_)(); 55 } 56 57 private: 58 Method method_; 59 }; 60 61 // Sorts the objects in |elements| using the method |method|, which must return 62 // a string. Sorting is done using a collator, unless a collator can not be 63 // found in which case the strings are sorted using the operator <. 64 template <class T, class Method> 65 void SortStringsUsingMethod(const std::string& locale, 66 std::vector<T*>* elements, 67 Method method) { 68 UErrorCode error = U_ZERO_ERROR; 69 icu::Locale loc(locale.c_str()); 70 scoped_ptr<icu::Collator> collator(icu::Collator::createInstance(loc, error)); 71 if (U_FAILURE(error)) { 72 sort(elements->begin(), elements->end(), 73 StringMethodComparator<T, Method>(method)); 74 return; 75 } 76 77 std::sort(elements->begin(), elements->end(), 78 StringMethodComparatorWithCollator<T, Method>(collator.get(), method)); 79 } 80 81 // Compares two elements' string keys and returns true if the first element's 82 // string key is less than the second element's string key. The Element must 83 // have a method like the follow format to return the string key. 84 // const string16& GetStringKey() const; 85 // This uses the locale specified in the constructor. 86 template <class Element> 87 class StringComparator : public std::binary_function<const Element&, 88 const Element&, 89 bool> { 90 public: 91 explicit StringComparator(icu::Collator* collator) 92 : collator_(collator) { } 93 94 // Returns true if lhs precedes rhs. 95 bool operator()(const Element& lhs, const Element& rhs) { 96 const string16& lhs_string_key = lhs.GetStringKey(); 97 const string16& rhs_string_key = rhs.GetStringKey(); 98 99 return StringComparator<string16>(collator_)(lhs_string_key, 100 rhs_string_key); 101 } 102 103 private: 104 icu::Collator* collator_; 105 }; 106 107 // Specialization of operator() method for string16 version. 108 template <> UI_EXPORT 109 bool StringComparator<string16>::operator()(const string16& lhs, 110 const string16& rhs); 111 112 // In place sorting of |elements| of a vector according to the string key of 113 // each element in the vector by using collation rules for |locale|. 114 // |begin_index| points to the start position of elements in the vector which 115 // want to be sorted. |end_index| points to the end position of elements in the 116 // vector which want to be sorted 117 template <class Element> 118 void SortVectorWithStringKey(const std::string& locale, 119 std::vector<Element>* elements, 120 unsigned int begin_index, 121 unsigned int end_index, 122 bool needs_stable_sort) { 123 DCHECK(begin_index < end_index && 124 end_index <= static_cast<unsigned int>(elements->size())); 125 UErrorCode error = U_ZERO_ERROR; 126 icu::Locale loc(locale.c_str()); 127 scoped_ptr<icu::Collator> collator(icu::Collator::createInstance(loc, error)); 128 if (U_FAILURE(error)) 129 collator.reset(); 130 StringComparator<Element> c(collator.get()); 131 if (needs_stable_sort) { 132 stable_sort(elements->begin() + begin_index, 133 elements->begin() + end_index, 134 c); 135 } else { 136 sort(elements->begin() + begin_index, elements->begin() + end_index, c); 137 } 138 } 139 140 template <class Element> 141 void SortVectorWithStringKey(const std::string& locale, 142 std::vector<Element>* elements, 143 bool needs_stable_sort) { 144 SortVectorWithStringKey<Element>(locale, elements, 0, elements->size(), 145 needs_stable_sort); 146 } 147 148 } // namespace l10n_util 149 150 #endif // UI_BASE_L10N_L10N_UTIL_COLLATOR_H_ 151